Clinicians’ assessments of bipolar disorder and substance abuse as predictors of suicidal behavior in acutely hospitalized psychiatric inpatients

Background Suicide is a major risk for those with bipolar disorder, a risk amplified by comorbid substance abuse in some, but not all, previous studies. To further explore the relationships of substance abuse, suicide, and bipolarity as they present in clinical practice, we analyzed standardized clinical data from a large acute psychiatric inpatient service. Methods Standardized clinical evaluations of 7819 patients with diagnoses of bipolar depression (n = 990), bipolar mania (n = 948), unipolar depressive episode (n = 3626), or schizophrenia-schizoaffective disorders (n = 2255) were analyzed to evaluate the relationship between current substance-use problems, substance-induced symptoms, and a current suicide crisis, as well as lifetime suicide attempts, with logistic regressions adjusting for age, gender, and ethnicity. Results Across the combined groups, current substance-use problems were significantly associated with a lifetime suicide attempt (odds ratios [ORs] 1.6–2.5) and to a lesser degree to the admission suicide crisis (ORs 1–2.2). Among bipolar (depressed/manic) patients, but not other diagnostic groups, those with both current substance-use problems and substance-induced symptoms had even higher rates of a recent suicide crisis (ORs 1.5–3.1) and of a lifetime attempt (ORs 2.5–3.4). Conclusions In bipolar patients, substance use disorder doubled and substance use disorder plus substance-induced symptoms tripled the suicidal risk. Implications for future research are discussed.